TODO List App

A sophisticated TODO list application built with Node.js 18 and Express 4.x, featuring a SQLite local database, full CRUD API, a responsive dark-themed UI, and comprehensive test coverage.

Tech Stack

Component	Technology	Version
Runtime	Node.js	18.x LTS
Framework	Express.js	4.18.x
Database	SQLite (via better-sqlite3)	9.x
Templating	EJS	3.x
Validation	express-validator	7.x
Testing	Jest + Supertest	29.x / 6.x
Linting	ESLint	8.x

Features

• Full CRUD operations for TODO items
• Priority levels: low, medium, high, urgent
• Tags, due dates, and descriptions
• Search and filtering (by status, priority, tags)
• Sortable and paginated list view
• Stats dashboard (total, pending, completed, overdue)
• Toggle completion status
• Bulk delete completed items
• Input validation on all endpoints
• Rate limiting, CORS, Helmet security headers
• Responsive dark-themed UI
• SQLite database with WAL mode for performance

---

Prerequisites

• Node.js 18.x (required — the app enforces this via engines in package.json)
• npm (comes with Node.js)
• nvm (recommended for managing Node versions)

Setup & Installation

1. Install Node.js 18

# Using nvm (recommended)
nvm install 18
nvm use 18

# Verify
node --version   # Should show v18.x.x

2. Install Dependencies

npm install

3. Initialize the Database

# Create the database and run migrations
npm run db:init

# (Optional) Seed with sample data
npm run db:seed

Running the App

Development Mode (with auto-reload)

npm run dev

Production Mode

NODE_ENV=production npm start

The app will start on http://localhost:3000 by default.

Environment Variables

Variable	Default	Description
PORT	3000	Server port
HOST	0.0.0.0	Server host
NODE_ENV	development	Environment (development/test/production)
DB_PATH	data/todo.db	SQLite database file path
RATE_LIMIT_WINDOW_MS	900000	Rate limit window (ms)
RATE_LIMIT_MAX	100	Max requests per window
CORS_ORIGIN	*	CORS allowed origin

---

Testing

Run All Tests

npm test

Run Tests with Coverage Report

npm run test:coverage

Run Tests in Watch Mode

npm run test:watch

Tests use a separate test database (data/todo-test.db) that is automatically created and cleaned up. The test suite covers:

• Create (POST): Valid creation, all fields, validation errors (missing title, invalid priority, bad dates, etc.)
• Read All (GET): Pagination, filtering by status/priority, search, sorting, validation of query params
• Read One (GET): Fetch by ID, 404 for missing, 400 for invalid UUID
• Update (PUT): Individual field updates, multi-field updates, timestamp changes, validation errors
• Toggle (PATCH): Toggle complete/incomplete, idempotency
• Delete One (DELETE): Successful deletion, verification of removal, 404 for missing
• Delete Completed (DELETE): Bulk deletion of completed items
• Stats (GET): Stats accuracy, count verification after operations
• Edge Cases: Large page numbers, XSS input, concurrent creates, tag filtering

---

Linting

# Check for lint errors
npm run lint

# Auto-fix lint errors
npm run lint:fix

---

Database Management

# Initialize database (create tables)
npm run db:init

# Seed database with sample data
npm run db:seed

# Reset database (delete and re-seed)
npm run db:reset

---

API Reference

Base URL: /api

List Todos

GET /api/todos?page=1&limit=20&sort=created_at&order=DESC&completed=false&priority=high&search=keyword&tag=work

Get Todo by ID

GET /api/todos/:id

Create Todo

POST /api/todos
Content-Type: application/json

{
  "title": "Buy groceries",
  "description": "Milk, eggs, bread",
  "priority": "high",
  "tags": ["shopping", "personal"],
  "due_date": "2025-01-15"
}

Update Todo

PUT /api/todos/:id
Content-Type: application/json

{
  "title": "Updated title",
  "completed": true,
  "priority": "urgent"
}

Toggle Completion

PATCH /api/todos/:id/toggle

Delete Todo

DELETE /api/todos/:id

Delete All Completed

DELETE /api/todos

Get Stats

GET /api/todos/stats

---

Project Structure

.
├── README.md
├── package.json
├── jest.config.js
├── .eslintrc.json
├── .nvmrc
├── .gitignore
├── src/
│   ├── server.js          # Entry point, starts HTTP server
│   ├── app.js             # Express app configuration
│   ├── config/
│   │   └── index.js       # Centralized configuration
│   ├── db/
│   │   ├── connection.js  # SQLite connection manager
│   │   ├── migrate.js     # Database migrations
│   │   ├── init.js        # Database initialization
│   │   ├── seed.js        # Sample data seeder
│   │   └── reset.js       # Database reset utility
│   ├── models/
│   │   └── todo.js        # Todo data model (CRUD operations)
│   ├── routes/
│   │   ├── api.js         # REST API routes
│   │   └── views.js       # View rendering routes
│   ├── middleware/
│   │   ├── errorHandler.js # Error handling middleware
│   │   └── validators.js  # Request validation middleware
│   ├── views/
│   │   ├── index.ejs      # Main page template
│   │   └── error.ejs      # Error page template
│   └── public/
│       ├── css/
│       │   └── styles.css # Application styles
│       └── js/
│           └── app.js     # Frontend JavaScript
└── tests/
    └── api.test.js        # API endpoint tests

---

License

MIT